[Adopted 10-2-1984 by Ord. No. 329 (Ch. 9, Part 1, of the
1983 Code)]
This article is enacted pursuant to standards of Title 25, Rules
and Regulations, Part I, Department of Environmental Protection, Subpart
C, Protection of Natural Resources, Article II, Water Resources, Chapter
102, Erosion and Sediment Control, and the Pennsylvania "Storm Water
Management Act" (1978, Oct. 4, P.L. 864, 32 P.S. § 680.1
et seq.) and regulations promulgated pursuant thereto and is designed
to comply with affirmative requirements imposed on municipalities
by said authority, and the purpose hereof is to regulate the modification
of natural terrain, the alteration of drainage, and to provide for
certain erosion, sedimentation and surface water runoff control and
containment within the Borough of Slippery Rock, Butler County, Pennsylvania.
From and after the effective date of this article, any building permit issued pursuant to Chapter
350, Subdivision and Land Development, of the Code of the Borough of Slippery Rock or separate grading permit issued pursuant to provisions hereof shall require conformance with this article as part of the terms and conditions. In the event of a conflict between this article and floodplain regulations, the floodplain regulation shall prevail.
The following terms, as used in this article, shall have the
meanings indicated, unless a different meaning clearly appears from
the context:
ALLUVIAL SOILS
An azonal great group of soils, developed from transported
and relatively recently deposited material (alluvium), characterized
by a weak modification (or none) of the original material by soil-forming
processes.
CUT and/or FILL
Process of earthmoving by excavating part of an area and/or
using excavated material for embankments of fill areas.
DEVELOPMENT
Any man-made change to improved or unimproved real estate,
including, but not limited to, buildings or other structures, mining,
dredging, filling, grading, paving, excavation or drilling operations.
EROSION
A.
The wearing away of the land surface by running water, wind,
ice, chemical or other geological agents;
B.
Detachment and movement of soil or rock fragments by water,
wind, ice or gravity.
FLOOD
A general but temporary condition of partial or complete
inundation of normally dry land area from the overflow of streams,
rivers or other waters of this commonwealth.
GENERAL FLOODPLAIN AREA
The one-hundred-year floodway and that maximum area of land
that is likely to be flooded by a one-hundred-year flood, as shown
on the floodplain maps.
GRADE
A.
The slope of a road, channel, or natural ground;
B.
The finished surface of a canal bed, roadbed, top of embankment,
or bottom of excavation; any surface prepared for the support of construction
like paving or laying a conduit;
C.
To finish the surface of a canal bed, roadbed, top of embankment,
or bottom or excavation.
OBSTRUCTION
Any structure or assembly of materials, including fill, above
or below the surface of land or water and an activity which might
impede, retard, or change flood flows. The planting, cultivation,
the harvesting of field and orchard crops or the grazing of livestock,
including the maintenance of necessary appurtenant agricultural fencing,
shall not be considered an obstruction under this definition and shall
not be subject to regulation under this article.
ONE-HUNDRED-YEAR FLOOD
The highest level of flooding that on the average is likely
to occur every 100 years, that is, that has a one-percent chance of
occurring each year.
ONE-HUNDRED-YEAR FLOODPLAIN or FLOODPLAIN
The one-hundred-year floodway and that maximum area of land
that is likely to be flooded by a one-hundred-year flood as shown
on the floodplain maps provided by FEMA to the municipality.
RUNOFF (HYDRAULICS)
That portion of the precipitation on a drainage area or watershed
that is discharged from the area in stream channels; types include
surface runoff, groundwater runoff, or seepage.
SEDIMENT
Solid material, both mineral and organic, that is in suspension,
is being transported, or has been moved from its site of origin by
air, water, gravity, or ice and has come to rest on the earth's
surface either above or below sea level.
SLOPE
Degree of deviation of a surface from the horizontal, usually
expressed in percent or degrees.
SOIL DRAINAGE
A condition of the soil, referring to the frequency and duration
of periods when the soil is free of saturation.
SUBSTANTIAL IMPROVEMENT
Any repair, reconstruction or improvement of a structure,
the cost of which equals or exceeds 50% of the market value of the
structure either before the improvement or repair is started, or,
if the structure has been damaged and is being restored, before the
damage occurred. For the purpose of this definition, substantial improvement
is considered to occur when the first alteration of any wall, ceiling,
floor, or other structural part of the building commences, whether
or not that alteration affects the external dimensions of the structure.
The term does not, however, include either any project for improvement
of a structure to comply with the existing state or local health,
sanitary or safety code specifications which are solely necessary
to assure safe living conditions or any alteration to a structure
listed on the National Register of Historic Places or the State Inventory
of Historic Places.
WATERCOURSE
A natural drainage route or channel for the flow of water.
WATERSHED
The entire region or area drained by a river or other body
of water, whether natural or artificial.
Whenever the landscape is to be permanently disturbed as to
either contours, soil or slope characteristics, or vegetation or any
ground cover is to be permanently removed, a plan is required showing
how resulting erosion and sediment shall be controlled. This plan
shall include the following:
A. The amount of site alteration proposed;
C. Erosion and sediment control practices (both temporary and permanent)
and the operation and maintenance arrangements.
The following activities require a grading permit:
A. Modifying, disturbing, blocking, diverting or otherwise adversely
affecting the natural overland or subsurface flow of stormwater;
B. Construction, erection, or installation of any drainage dam, ditch,
culvert, drainpipe, bridge or any other structure or obstruction affecting
the drainage of any premises;
C. Paving, filling, stripping, excavating, grading and regrading of
any land;
D. Disturbing the landscape, vegetation or any ground cover by any proposal
involving an area in excess of 25,000 square feet.
The following activities require no grading permit:
A. Improvements, such as erection of retaining walls, driveway paving,
minor regrading or activities on a property which do not adversely
affect the natural overland or subsurface flow of stormwater, drainage
of any premises, or adversely disturb the landscape, in a gross area
of up to 25,000 square feet on any one property.
B. Farming, gardening, or lawn restoration, but not including sod farming.
The plan for a grading permit shall include:
A. A valid boundary line survey of the site on which the work is to
be performed;
B. A description of the features, existing and proposed, surrounding
the site which are of importance to the proposed development;
C. A plan of the general topography (including drainage) and soil conditions
on the site (latter available through the County Conservation District);
D. The location and a description of existing and future man-made features
of importance to the proposed development (i.e., cuts and/or fills,
buildings, roads, and driveways);
E. Plans and specifications of soil erosion and sediment control measures
in accordance with standards and specifications of the Borough of
Slippery Rock and the County Conversation District;
F. A development schedule indicating the anticipated starting and completion
dates of the development sequence and the time of exposure of each
area prior to the completion of effective erosion and sediment control
measures.
In addition to the requirements aforesaid, and where deemed
necessary by the Borough Engineer and the Planning Commission, the
applicant shall submit, with the plan, a detailed stormwater management
plan prepared by a registered professional engineer qualified in hydrology
in the commonwealth. This plan shall include:
A. A plan of the property showing the location of all present and proposed
ditches, streams, pipes and other drainage structures, and proposed
cuts and/or fills. In addition to showing present elevations and dimensions,
and location and extent of all proposed grading and/or drainage, the
plan shall clearly indicate all woodlands, buildings, parking areas
and driveways. Further, the plan shall indicate the present and proposed
sources, storage and disposition of water being channeled through
or across the premises, together with elevations, gradients, and maximum
flow rates. The plan shall describe the work to be performed and disposition
of cut and/or fill, the materials to be used and the manner or method
of performance, including provisions for protecting and maintaining
existing drainage facilities, whether on public or private property.
The applicant shall also supply the supporting data for the plan as
developed by the Engineer.
B. Calculations to determine runoff, which shall be based on the Soil-Cover
Complex Method, a description of which is available from the USDA
Natural Resources Conservation Service and outlined in the "Erosion
and Sediment Control Handbook, Butler, Pennsylvania."
(1) The design criteria for storm sewer piping on inlet systems within
a subdivision being developed shall be designed for a twenty-five-year
frequency storm; culverts across roadways shall be designed for a
fifty-year frequency storm; open watercourses or swales shall be designed
for a one-hundred-year frequency storm as prescribed in accordance
with the following:
(a)
The coefficient of runoff used for all areas upstream of any
drainage structure shall be computed on the basis of existing land
use and the projected land use described and shown on the Slippery
Rock Borough Comprehensive Plan and adjacent municipalities'
Comprehensive Plans, where applicable.
(2) The following provisions apply to the carrying and disposal of stormwater
runoff:
(a)
All drainage facilities shall be designed to carry surface water
in such a manner as to prevent erosion or overflow.
(b)
The applicant shall agree to the granting and recording of easements
covering the installation and maintenance of drainage facilities.
(c)
The rate of runoff shall be no greater during and after a one-hundred-year
frequency storm when the development is completed than which existed
before the development began, and appropriate measurements of calculations
shall be provided to verify such provisions.
C. A soils investigation report, if load-bearing fill is proposed, which
shall consist of test borings, laboratory testings and engineering
analysis to correlate surface and subsurface conditions with the proposed
grading plan. The results of the investigation shall be presented
in a report by a registered professional soils engineer and shall
include data regarding the nature, distribution and supporting ability
of existing soils and rocks on the site, conclusions and recommendations
to insure stable soil conditions and groundwater control as applicable.
Slippery Rock Borough may require such supplemental reports and data
as is deemed necessary by the Borough Engineer. Recommendations included
in such reports and approved by the Borough Engineer shall be incorporated
in the plan or specifications. In addition:
(1) Fills toeing out on natural slopes steeper than four horizontal to
one vertical shall not be made unless a report is received which is
deemed acceptable by the Borough Engineer and approved by the Borough
Council. The report shall be made by a registered professional soils
engineer certifying that he has investigated the property, made solid
tests and that in his opinion such steeper slopes will safely support
the proposed fill.
(2) Natural and/or existing slopes exceeding five horizontal to one vertical
shall be benched or continuously stepped into competent materials
prior to placing all classes of fill.
The application shall contain a statement of indemnity by the
applicant wherein the owner or developer/owner legally agrees to hold
the Borough harmless from any and all liability relating to flood
damage or loss, or from loss relating to storm drainage systems and
their discharge during construction of the system and thereafter.
Upon the approval of the plan by the Borough Engineer, the Zoning
Officer shall issue the necessary grading permit.
Permittees shall bear all costs of inspections required or permitted
hereunder and shall deposit with the Borough such sum as the Borough
shall determine to guarantee payment of the costs of such inspections.
The costs of inspections shall be in accordance with the established
schedule of fees and collection procedure for matters pertaining to
this article.
The fee for a grading permit shall be fixed by resolution of
the Borough from time to time.
Any person, firm or corporation who shall violate any provision
of this article shall, upon conviction thereof, be sentenced to pay
a fine of not more than $300 and/or to undergo imprisonment for a
term not exceeding 90 days. Each day that a violation of this article
continues shall constitute a separate offense.
In addition to the penalties as set forth in §
309-19, any movement of the landscape, vegetation, or any ground cover performed in violation of this article shall be restored to its previous condition, including replacement of excavating earth, removal of illegally placed fill, and restoration of grades and planting.
This article shall become effective on November 2, 1984.